85 evunrude low hours

[Stassson]

Hi I have a 85 evinrude 175V6. nothing has ever been done to it other then spark plugs.Is there anything that I shpould replace becuase of the age? Also it seems to take for ever for it to hit 4000RPM wich is also the single that it is ready to get up on plane. I full throtle it but it does race to 4 thousand . Is this just the age or do the coils nee to be replaced. I love the boat and morotr and am going to start to replace every thing little by little. Is there anything I can do to speed the motor up or get better fuel milage . Thanks

 

[DJ]

Re: 85 evunrude low hours

Stasson,<br /><br />That engine should turn upwards of 5500 rpm.<br /><br />I take it you've owned it for a while?? Did it ever go over 4000?<br /><br />I can think of several things to do.<br /><br />1. Change the water pump impeller.<br /><br />2. Change the gear lube, with new seals for the plugs (drain annd fill).<br /><br />3. Your carburetors are probably do for an overhaul. That may be your running problem.

 

[Stassson]

Re: 85 evunrude low hours

Djohns19 All those things have been done I was told not to run it over 4900 and it does run upto 5100 with the 15+19 picth prop going upto a 19 to slow down the rpm's I was thinking maybe more the coil and powerpacks maybe thanks Stas

 

[Spidybot]

Re: 85 evunrude low hours

It's supposed to do 4500-5500. Fitting a higher pitch will bring down rpm at WOT but certainly also will increase the time to reach it. It is no good idea to fit a prop that makes your motor WOT below the recommended range as you put a large stress on it (lugging). Rather a little high on the rpm than lugging. Over time lugging will damage your motor. A motor running a little higher on a lighter load has much better conditions for all parts (pistons, bearings etc.)

 

[SeaMasterZ@aol.com]

Re: 85 evunrude low hours

on those big boy outboards,arent they overbuilt and able to keep torque rolling along at 3500? I agree, lugging is bad, but I thought the bigger outboards were built for it.

 

[Spidybot]

Re: 85 evunrude low hours

No - there is no 'legal' reason for lugging. No matter the size, the recommended WOT rpm are to be taken seriously. 3500 can be OK if the boat/prop/setup does not make the motor work under severe stress, but not at WOT unless specified (can't think of any motor with recommended 3500 at WOT). Like riding a mountainbike: You choose the gear that makes your effort easy. Your boat only has one 'gear', designed to allow the right rpm at WOT. By using a too high pitch prop you risc lugging all the time, difficulties getting on plane and running WOT all the time just to keep it on plane. What most experience with the right prop is pretty good hole shot, fairly fast on plane and good-mpg cruising on plane at approx. 3/4 throttle or less. All depending on boat weight/hp ratio, ofcourse.

 

[OBJ]

Re: 85 evunrude low hours

Hi Stasson...<br /><br />Just an operation type question....are you using the TNT? The engine should be trimmed all the way in at throttle up and start trimming out as the boat starts up on the pads. Leaving the engine trimmed in will cause your problem. If the engine ran at 5100rpm before with the current prop, I see no need for changing pitch.